function submit_form() {
    let name = document.getElementById("username").value;
    let pwd = document.getElementById("password").value;
    let rpwd = document.getElementById("repassword").value;
    if(name == '' || pwd == '' || rpwd == ''){
        alert("请输入完整！");
        return false;
    }else if(pwd != rpwd){
        alert("密码不一致！");
        return false;
    }
}